REVIT IFC MANUAL

Revit IFC manual 

Detailed instructions for handling IFC files 

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CONTENTS 

1. INTRODUCTION ....................................................................... 3 

2. THE BASICS .............................................................................. 5 

2.1 IFC file formats 5 

2.2 IFC versions (schema) 5 

2.3 Model view definition (MVD) 6 

2.4 IFC structure 8 

2.4.1 IFC classes and types 9 

2.4.2 Geometric representation of IFC items 10 

2.4.3 Default attributes 11 

2.4.4 Reference structure within an IFC file 14 

2.5 LOD 14 

2.6 Open-source IFCs 15 

2.7 IFC viewers 16 

3 LINKING IFC FILES IN REVIT................................................ 17 

4 OPENING IFC FILES................................................................. 18 

4.1 Mapping table 18 

4.2 Import options 19 

5 EXPORTING IFC FILES............................................................. 22 

5.1 Mapping tables 22 

5.2 Revit IFC exporter settings 25 

5.2.1 General settings 26 

5.2.2 Additional content 31 

5.2.3 Property sets 32 

5.2.4 Level of detail 37 

5.2.5 Advanced settings 38 

5.3 Other settings 40 

6 EXAMPLES OF APPLICATIONS .............................................. 44 

6.1 Floor slab construction 44 

6.2 Aperture planning 45 

6.3 Assigning assemblies 47 

6.4 Assigning default attributes 48 

6.5 Structuring the IFC data model 50 

6.6 Usage groups in the IFC data model 51 

7 SUMMARY ................................................................................. 52 

INSTRUCTIONS FOR REVIT USERS


1. INTRODUCTION 

BIM (Building Information Modeling) is an intelligent 3D model-based process that gives 

architecture, engineering, and construction (AEC) professionals the insight and tools to more 

efficiently plan, design, construct, and manage buildings and infrastructure. At the heart of BIM is 

a smart building data model that incorporates not only 3D geometry but also all the relevant data 

relating to the building and its components. This kind of building data model can only be created 

using complex, BIM-enabled software such as Autodesk Revit ® . 

Provided that all of those involved in the 

planning are working with the same software, 

data exchange is loss-free. The native BIM 

format also facilitates the coordination of all 

planning stages and stakeholders. 

In building projects, it can happen that 

those involved in the planning process are 

using different BIM software from different 

providers. The buildingSMART initiative (www. 

buildingSMART.org), in which Autodesk has 

been actively involved from the very outset, 

has developed the IFC format to support such 

openBIM workflows. IFC allows the exchange 

of a specific subset of the native model. 

Since the IFC4 release, the IFC format has met 

a recognized ISO standard (ISO 16739:2013). In 

its current version, buildingSMART maintains a 

list of all applications with certified IFC support: 

www.buildingsmart.org/compliance/certifiedsoftware/ 

IFC as the standard for exchanging BIM information 

The Industry Foundation Classes (IFC) are an open standard for the exchange of building data models 

used in building design and construction across different software. They are used to exchange 

information within a project team and between software applications used in design, construction, 

procurement, maintenance, and operation. Current IFC Model View Definitions primarily support 3D 

geometry and property data. If exchange of 2D information, such as plan views and annotations, 

is important, Revit and coordination tools such as Autodesk BIM 360 which support the native file 

format should be preferred. 



With IFC, the standard workflow is as per this model: 

Native format 

IFC 

Coordination/ 

No editing 

Find out more on the buildingSMART website: 

https://www.buildingsmart.org/users/international-user-group-faqs/ 

Using IFC in practice 

In an ideal scenario, the IFC file should be used 

for coordination purposes in an IFC viewer or 

as a reference within the editor software. For 

instance, the architect would receive an IFC file 

from the building equipment engineer, allowing 

them to see where the installation is placed. 

This workflow is referred to as the coordination 

workflow and is covered with the Coordination 

Model Views in IFC. 

In some cases they may be the need for a design 

transfer workflow, for example if the architect 

had created the design in another software, but 

needs to carry on planning the building in Revit. 

This is the more difficult workflow and often 

requires manual adjustments to deal with the 

differences in software. 

The Revit IFC manual 

This document is intended to serve as a guide 

for Revit users handling IFC data and providing 

a better understanding of the settings available 

in Revit, discussing the way they can influence 

the quality and the content of the IFC file. The 

Revit IFC manual therefore sets out the basics 

of IFC and explains in detail how to export, link 

and open IFC files in Revit. 



2. THE BASICS 

The key considerations when using an IFC file are the file format, IFC version, model view definitions, 

and file structure. We explain all these on the following pages. 

2.1 IFC file formats 

.ifc 

Standard format, based on STEP (STEP: Standard for the Exchange of 

Product Model Data). 

.ifcZIP 

Compressed IFC files with much smaller file size; can be read by most 

software applications that support IFC. It can be unpacked to make the 

uncompressed IFC file visible. 

.ifcXML 

XML-based representation of IFC data, required by certain calculation 

software. 

2.2 IFC versions (schema) 

The IFC definitions are regularly updated and developed by buildingSMART. It is recommended that 

you use the latest versions wherever possible. Among other things, the IFC4 format allows better 

representation of complex geometries. 

Current versions: 

• IFC4 (still in beta, certification process in progress, offers certain advanced possibilities but is 

not widely supported yet); 

• IFC2x3 (currently the most supported and stable format, certified in Revit and recommended for 

production); 

• IFC2x2 (recommended if the recipient of the file does not have software with IFC2x3 or IFC4 

support). 

Revit no longer supports the following older versions: IFC2.0 (import still supported), IFC1.5.1, 

IFC1.5, and IFC1.0 



2.3 Model view definition (MVD) 

In addition to the file format and versions, the 

model view definition determines how you use 

an IFC file, because it enables a specific data 

exchange scenario. 

MVDs are used for the targeted exchange 

of specialized models, taking account of the 

graphic and content-related information that 

the planner needs. 

For instance, thermal simulations require 

information about lighting areas in a wall and a 

room. Conversely, specialized IFC models require 

only the basic geometric information to be 

transferred to an FM system, and focus instead 

on spatial information and specific component 

features (such as system information, fire 

protection features, and usable areas) in relation 

to the MVDs. Moreover, a specialized model for 

structure planning requires specific information 

about the supporting building elements and 

apertures. 

The official, buildingSMART-defined MVDs available in Revit are listed below. 

IFC4: Model Reference View 

The model reference view was designed for 

the standard delivery of a reference model for 

specialist planners in IFC4. In the first instance, 

it provides an IFC model for coordination 

and model-based quantity determination, as 

referred to in the modeling software. A model 

exported as a Model Reference View is not 

suitable for importing with the intention of 

conducting further work on the geometry, as 

it contains only the most essential geometric 

definitions. 

The model is not necessarily heavily simplified 

in graphic terms; it serves merely as a reference 

that may be quite detailed but cannot be edited. 



IFC4: Design Transfer View (beta) 

Introduced for the first time with IFC4, this is 

used to transfer IFC models for the purpose 

of importing and editing them in BIM-enabled 

software. As previously mentioned, the ability 

to transmit parametric design and complex 

contexts is restricted in the IFC format, so some 

manual adjustments will be needed to deal with 

differences in software, and the data should 

always be manually verified. 

IFC2x3 COBie 2.4 Design Deliverable 

IFC format equivalent to the COBie (Construction 

Operations Building Information Exchange) 

output required by the UK government for their 

2016 Level 2 BIM mandate for collaboration on 

public-sector work. 

For exporting in COBie format, the relevant addon 

from http://www.biminteroperabilitytools.com 

can also be installed. 

IFC2x3 Coordination View Version 2.0 

Optimized for the coordinated exchange of BIM 

models between the main disciplines in the 

building industry. Coordination View 2.0—also 

known as CV 2.0—is currently the most widely 

used and supported Model View Definition. CV 2.0 

supports the rudimentary parametric derivation 

of building components when importing into 

planning tools. 

This MVD is primarily used for exchanging 

architectural, building technology, and 

construction engineering models. 

IFC2x2 Coordination View 

Used only in isolated cases, such as when 

exporting MVDs for software that does not 

support IFC2x3. 

Each of these model view definitions (MVDs) 

can naturally be adapted to the needs of the 

workflows—more information on this can be 

found in the following chapter, “Exporting IFC 

files.” 

To identify which MVD is used by an existing IFC file, you can open the file in a text editor of your 

choice. The header contains all the information about the MVD, the exact IFC exporter version and 

the software that it has been exported from: 

FILE_DESCRIPTION((‘ViewDefinition [ReferenceView_V1.0]’),‘2;1’); 

FILE_NAME(‘Project Number’,‘2016-12-14T17:37:10’,(‚‘),(‚‘),‘The EXPRESS Data Manager Version 5.02.0100.07: 

28 Aug 2013’,‘20161006_0315(x64) - Exporter 17.2.0.0 - Alternate UI 17.2.0.0’,’’); 

FILE_SCHEMA((‘IFC4’)); 

ENDSEC; 

DATA; 

#1= IFCORGANIZATION($,‘Autodesk Revit 2017 (ENU)’,$,$,$); 

#5= IFCAPPLICATION(#1,‘2017’,‘Autodesk Revit 2017 (ENU)’,‘Revit’); 



2.4 IFC structure 

IFC files create a building model based on a pre-defined structure that builds the model in a logical 

way. When it is saved, the IFC file format orders the IFC units hierarchically according to their type, 

as follows. 

For a list of all buildingSMART-defined classes, see 

https://autode.sk/IFClinks. 

This page also allows you to install all Revit-supported entities that can be used for export. 



2.4.1 IFC classes and types 

An IFC entity is a uniquely defined object in the IFC data model. Depending on the entity assignment 

and type definition, the object is allocated certain default attributes and dependencies within the 

IFC schema. 

Choosing the right entity is crucial when 

exporting IFCs: if a wall is not assigned to the 

entity IfcWall, it is not allocated all the attributes 

that it requires to be described clearly. This 

means that it is not interpreted correctly by 

other coordination or evaluation programs in 

turn. 

Distinctions are not only made between major 

categories, so components can also be assigned 

as entities to reproduce them more accurately 

within the IFC data model. This classification 

can roughly be compared to the sub-categories 

in Revit. A foundation of the IfcFooting entity 

can also be shown, depending on the type of 

component and its intended use, for instance by 

specifying the Ifc type as a sleeve foundation, 

“PILE_CAP”. 

Complex structures emerge on the basis of this 

system, enabling the generation of a data model 

in which every element can be geometrically 

and alphanumerically represented and clearly 

identified. 



2.4.2 Geometric representation of IFC objects 

There are three basic possibilities for geometrically representing a three-dimensional IFC object: 

- extrusions 

- solid body representation using a sweep, and 

- representation using B-reps. 

Extrusions 

Are the most common and simple graphical method and are used for most of the cases when the shape 

can be described by a simple profile. 

Swept solids 

As the name implies, an element is created with the swept solid 

method using a sweep. In this case, a defined profile is led along a 

path (direction vector) to generate the solid. This profile may change 

due to rotation or distortion along the path. Revit uses this method 

for describing rebar and other shapes which cannot be described 

with extrusions. 

B-rep 

The method known as boundary representation (B-rep) can also be 

described as a boundary surface model. The surfaces of a component 

are represented using coordinates and together form the actual solid, 

allowing even complex forms to be represented. 

B-rep objects use complex calculations to represent individual 

surfaces in detail, and thus use more data memory. 

NURBS and other smooth surfaces 

In the IFC4 schema, it is possible to generate B-rep objects as 

advanced B-reps using NURBS (non-uniform rational B-splines) 

surfaces. The memory space required is thus drastically reduced, 

while the bodies are represented more accurately. 



2.4.3 Default attributes and parameters 

One of the key considerations when transferring IFC data models is the provision of information 

that can be correctly interpreted and evaluated by specialist planners and their planning and 

calculation tools, regardless of the internal attribute structure and descriptions within the respective 

applications. 

IFC properties can be formulated across the board using default attributes. These attributes are 

stored in the IFC definition and have English names. 

Some BIM applications can automatically assign internal attributes to IFC-compliant default 

attributes. This ensures that the necessary information is provided to represent an object. 

When exporting an object out of Revit, not only is all the necessary information relating to 

classification, global location, and geometric representation transferred, but also default attributes. 

For instance, for a wall the value from the instance parameter ‘supporting’ is automatically assigned 

to the IFC attribute LoadBearing. 

Please note that the IFC 

exporter only transmits valid 

property values, i.e. those that 

are not empty. If the parameter 

is missing from your IFC file, 

this is likely because the Revit 

parameter does not have a 

value. This optimizes the file 

size, as empty data fields are 

not exported. 



An overview of all default parameters defined in IFC format is provided by buildingSMART in the 

form of parameter sets (P-sets). 

As an example, these are the default parameters for a wall: 

Pset_WallCommon 

Default parameters in Revit: 

Reference 

Component type (type name) 

FireRating 

Fire-resistance class (type parameter) 

ThermalTransmittance U-value (type parameter) 

IsExternal 

Exterior component (type parameter, given as yes/no) 

LoadBearing 

Load-bearing (instance parameter) 

ExtendToStructure Fixed on top (behavior) 

The following parameters are also part of the Pset_WallCommon, but are either unavailable or not 

assigned by default in Revit: 

AcousticRating 

Sound insulation class 

Combustible 

Combustible material 

SurfaceSpreadOfFlame Fire behavior 

Compartmentation Fire compartment-defining component 

In order to create these parameters in Revit, they have to be created using the exact name, the 

correct type (text/number/yes/no, visible in the buildingSMART documentation): 

Additional IFC parameters in Revit 

IFC properties after exporting in FZK Viewer 



As soon as these parameters are available and have a value, they are taken into account in the export. 

The advantage of this standardization is that the parameters of other programs are automatically 

recognized and assigned correctly. Since version v18.4.0 the Autodesk IFC Export supports all 

common property set defined in the IFC schema. 

Thanks to the extensive settings of the Revit IFC exporter, other parameters that do not appear on 

this list can be exported. This is covered in greater detail in Chapter 4, “Exporting IFC files.” 

2.4.4 Reference structure within an IFC file 

An IFC file can be opened in a text editor. This can be very helpful for analysis or troubleshooting. 

There are two parts to the underlying structure of an IFC file: the header and the body. While the 

header contains general information about the building model, the IFC version and software used, 

the schema, and the MVD, the body contains the information about the geometry and attributes 

of the building itself. 

In IFC format, the description of an element begins with a line that classifies, uniquely identifies, 

and names the object. Our wall example might look like this: 

#177= IFCWALLSTANDARDCASE(‚1sfW$3YQj9jBEISmjkeABP‘,#41,‘Basiswand:STB 

20.0:388701‘,$,‘Basiswand:STB 20.0:3895‘,#146,#173,‘388701‘); 

Within this definition line, the wall object refers to other lines in the file structure, distinguishable 

by the # that precedes them. These describe it in greater detail and refer in turn to other lines: 

#146= IFCLOCALPLACEMENT(#128,#145); → Reference to the lines that define the global position 

#173= IFCPRODUCTDEFINITIONSHAPE($,$,(#152,#170)); → Reference to lines that provide a 

geometric description of the wall 

This reference structure continues until a logical data model has been generated that provides a 

clear description of each object. 

The advantage of this method is that particular attributes are stored only once and can be used 

by other components by means of referencing. This significantly reduces the file size and means, 

for instance, that components with the same material refer to the same material definition lines 

within the data model. 



2.5 Open-source IFCs 

Revit comes with an integrated IFC interface whose functionality can be extended using the Open 

Source extension. Another advantage of this plug-in is that it is constantly being developed and is 

regularly updated by Autodesk, regardless of Revit update cycles. 

Developers can access the complete source code and customize the exporter as required. This is 

especially useful if specific workflows require this kind of customization for a construction project. 

If you are working with IFC files in Revit, you 

should first install the latest version of the 

Open Source extension. This can be found in 

the Autodesk AppStore: 

http://apps.autodesk.com 

After installation, you will not see a new icon 

in Revit. Instead, the plug-in overwrites the 

standard dialog fields. If you are a developer 

and want to work with the source code, you can 

find additional information on SourceForge: 

https://sourceforge.net/projects/ifcexporter: 

If working with IFC files, it is important that 

you are not only informed about their structure 

(MVD) and version, but also that you are aware 

of the possibilities and importance of the 

individual export and import options. You will 

only get an IFC file with all the information 

that you need if you use the right settings. The 

following chapters show you how to do this. 



2.6 IFC viewers 

Before you pass an IFC file on to planning partners or use it yourself in Revit, you are advised to 

test it in an IFC viewer and check the export result. 

There are a range of IFC viewers on the market. These viewers support certain IFC functions with 

different levels of effectiveness, depending on their focus. 

As Autodesk customers, you have access to Navisworks as part of the AEC Collection. Navisworks 

can be used not only to view IFC files, but also to carry out collision testing, create construction 

workflow simulations and determine quantities. 

As part of the Autodesk BIM 360 services, you can also view and share IFC files (and many other 

formats) directly in your browser. 

© London Blackfriars station, courtesy of Network Rail and Jacobs ® 

The FZK Viewer, created by the Karlsruhe Institute of Technology (KIT), has established itself as an 

open-source, independent viewer. It is highly streamlined and manageable, and is therefore well 

suited to checking small to medium-sized models quickly. It was used for some of the screenshots 

that appear in this manual. 

The current version of the FZK Viewer can be downloaded from the KIT website: 

www.iai.kit.edu 



3. LINKING IFC FILES IN REVIT 

Besides Revit models and CAD data (2D/3D), you can also link IFC models in a Revit project: 

This option links the IFC file within the Revit project, so that updates are possible at a later 

date. This process is similar to the linking of other Revit or CAD files with Revit. You can find 

the linked IFC file in the project browser: 

The IFC file is automatically updated at the start of the project and can be manually updated 

at any time during editing. To do this, select the IFC file in the project browser and reload it via 

the context menu (right-click). Revit automatically creates a Revit file in the same folder, which 

contains the IFC file: 

You should not move, change, or open this file. 

Linking IFC files is the preferred option for coordination purposes and gives the best results because 

it does not generate native Revit elements. 

There are no detailed settings for the linking of IFC files, as the system automatically generates the 

best result. 

The maker’s export settings play a far greater role in the quality of the linked file. 

When linking an IFC specialist model, a “shared parameters” file is created at the location of the 

IFC file. This can be used to create filters that allow the selection, graphic overwriting, or hiding of 

components from the linked specialist model. Specific examples of applications can be found in the 

final chapter of this manual. 



4. OPENING IFC FILES 

In some cases, it is necessary to open the IFC 

file in Revit to continue editing it. This may be 

the case if the architect has created the design 

using different software but now intends to 

carry on planning the building in Revit. 

As already mentioned in the Introduction, this 

workflow does not come fully recommended 

as the model loses some of its intelligence 

and parametrics when it is exported to the IFC 

format. In some cases, however, an imported IFC 

model can prove a good foundation for further 

planning. When importing, Revit transforms 

each element contained in the IFC file into a 

native Revit object. For this reason, importing 

large models can also be quite time-consuming. 

Ultimately, the quality of the import depends 

very much on the quality (export settings) and 

the content (IFC version, MVD). 



4.1 Mapping table 

The mapping table for IFC imports is structured in a similar way to the export mapping table and can 

be called up via Revit > Open > IFC options: 

4.2 Import options 

The Open dialog window offers a few options that can help you handle IFC files in Revit. 



AutoJoin elements 

connects walls, supports and other elements 

automatically using the same approach as that 

applied in the Revit modeling. This can lead to 

undesirable results for complex structures or 

long export times, so this option can be disabled 

if necessary. 

Correct lines that are slightly off axis 

is an option that will be familiar from the link/ 

import CAD function, and seeks to correct 

elements that deviate slightly from the main 

axis. This option can be disabled if necessary, 

as it can lead to problems with elements which 

are meant to be off axis, like site boundaries for 

example. 

The quality of the imported data depends not only on the 

import settings, but also to a large degree on the export 

settings and the modeling method applied in the original 

software. 

The Revit–IFC import interface is regularly updated 

together with the export module, but is also subject to 

the limits of technical feasibility and the IFC format. It is 

not possible for a standardized format to transfer complex 

parametrics and contexts. 

For example: 

To create a floor slab in Autodesk 

Revit, a profile is sketched and 

is generated (or extruded) at a 

right angle to the profile, taking 

into account the component types 

and the defined layer thickness. 

Autodesk Revit generates standard 

floor slabs on the basis of this 

principle. 

Essentially, in most cases this workflow represents a good 

working basis. If IFC data have to be processed further, 

one should always expect the loss of data in comparison 

with the original software. 

This approach is very similar to 

that seen in the IFC schema, and 

typically gives optimum results, 

generating clean standard floor 

slabs in Revit. 



As planning proceeds, the slab is given an opening and a gradient, with the underside remaining 

naturally flat. Within the IFC schema, representing this component as a swept solid, in other words 

generating a solid using a defined profile and pathway, is no longer possible. 

The element is thus described as a B-rep object in 

the data model, with all the necessary geometry 

points. When importing, the slab is recognized 

on the basis of its object class (IfcSlab) and 

assigned to the correct category. However, the 

geometric description no longer corresponds to 

the basic principle for creating a floor slab, so a 

project family is generated. 

This is not a fundamental problem, especially in 

terms of coordination, as the slab is correctly 

represented. Nonetheless, if you want to edit 

the imported slab, certain limitations arise, as 

you cannot work on it using the normal tools. 

Recommendations for construction 

“Edit profile” and “Edit surface” are very useful 

tools in the geometric processing of wall and 

Recommendations on construction 

Edit profile and Edit Footprint are very 

useful tools when it comes to modifying 

the geometry of wall and ceiling elements. 

However, these functions can make the 

planner’s life particularly difficult when 

it comes to exchanging specialist models 

by importing or exporting IFC files, as 

geometries may be incorrectly interpreted 

or represented. 

Likewise, an opening sketched using editing 

tools will not always result in the generation 

of an “Opening element,” as it would in the 

case of a void form. 



5. EXPORTING IFC FILES 

When choosing the right settings for exporting an IFC file, it is important to first think about what 

the file is to be used for: Will it be used only for the purposes of coordination, or does it have to be 

processed using a different editor software? Below you can see the impact of the respective mapping 

and export settings, together with the available options. 

5.1 Mapping tables 

Before exporting an IFC 

file, it is important to check 

the settings. You can find 

these at: Revit > Export > 

Options > IFC options. 



Revit categories are assigned to IFC classes using a mapping table. This table is stored as a text file 

(*.txt) and can be customized directly in Revit or by using a text editor. 

The first column, the Revit category, is 

unchangeable and automatically lists all the 

categories and sub-categories available in the 

Revit project. 

of the contents and structure of the IFC model, 

and therefore cannot be specified across the 

board. However, Revit is delivered with basic 

settings that meet a certain basic standard. 

The IFC class name column contains the IFC class 

to which the sub-category or category should be 

assigned. If the category is not to be exported, 

you can enter Not Exported. This can vary 

depending on the workflow and requirements 

The IFC classes and types must be entered 

manually, with the correct spelling. This is how 

footings from the IFC class become assigned to 

the IfcFooting. The list of classes supported in 

Revit is regularly updated and can be called up 



here for version 2019: https://autode.sk/IFClinks. 

An IFC type can also be assigned which, like the 

sub-categories in Revit, allows more accurate 

differentiation within a category. For a pile cap, 

the type “PILE_CAP” can thus be specified in 

addition to the category IfcFooting. 

The types available in IFC format can be 

checked for their respective IFC release on the 

buildingSMART page. Current links and lists can 

be found at https://autode.sk/IFClinks. 

It is worth noting that unlike Revit, certain BIM 

programs do not only work with categories, but 

also with the layers used in CAD operations. 

When exporting IFCs from Revit, the settings 

file that was also used when exporting the CAD 

(.dwg or .dgn) is accessed. This file is defined 

in the Revit.ini and can be changed there if 

required. The default configuration file can also 

either be customized or another configuration 

specified. 

The pre-configured mapping table is stored by 

default via the system path C:\ProgramData\ 

Autodesk\RVT(Version)\exportlayers-ifc-IAI. 

txt. A standardized export can be performed 

across different companies using a centrally 

stored mapping table. 

The default configuration file for Revit 2018 

can be found at C:\ProgramData\Autodesk\RVT 

2018\exportlayers-dwg-AIA.txt 

The configuration can also be customized and 

exported via the Revit dialog, which can be 

found at > Export > Options > Export settings 

DWG/DXF: 



To refer to a different configuration file, change 

the following path in the Revit.ini file using 

a text editor: ExportLayersNameDGN=C:\ 

ProgramData\Autodesk\RVT 2018\exportlayersdwg-AIA.txt 

The Revit.ini for the 2018 version is located 

at C:\Users\\AppData\Roaming\ 

Autodesk\Revit\RVT 2018 

As this is a hidden folder by default in Windows, 

the display of hidden folders has to be activated 

beforehand. 

To completely reset the Revit.ini, the file can be 

deleted under the aforementioned path. It will 

be recreated after restarting Revit. 

5.2 Revit IFC exporter settings 

A project opened in Revit can be exported via File > Export > IFC. Extensive settings are possible in 

the subsequent dialog, explained in greater detail below. 

Main dialog 

First, this main window opens: 



The desired name and file location of the IFC file 

to be exported are specified under File name. 

Current selected setup: allows export according 

to preset configurations. The selection of the 

schema and MVD to be used is crucial in defining 

the content and structure of the IFC file and 

should therefore be coordinated and chosen 

according to their intended use. 

Modify setup: these settings can be adapted if 

required and custom definitions can be created, 

which are stored with the Revit project. 

Projects to export: Here you can choose projects 

that are currently open in Revit and are to be 

exported. When exporting several projects, the 

same settings are used for all files, and saved to 

an IFC file. 

Modify setup 

Individual settings for IFC export can be made and saved in the Modify setup window. 

All the pre-installed configurations are displayed on the left-hand side. The default configurations 

are marked with brackets and cannot be changed, renamed or deleted. However, they can be copied 

and thus used as the basis for custom configurations. In addition, you can export or import previously 

created settings, which are stored outside of the Revit project. 

5.2.1 General settings 

The following general settings can be found in the general tab for Advanced IFC export settings: 



The IFC version allows you to select the IFC 

schema and the MVD, as explained in detail 

earlier in this manual. The most commonly used 

schema is IFC 2x3 Coordination View 2.0, as it 

is supported by most programs. For complex 

geometries, you can try to use IFC4 because of 

improvements to the geometry translation, but 

keep in mind that is still in beta and double check 

the result for any errors or missing elements. 

The file type determines the file format in which 

the exported file will be saved. For big projects, 

the compressed *.ifczip format can be used, 

which is also supported by most IFC viewers. If 

required, the *.ifczip file can be unzipped to get 

the uncompressed *.ifc file. 

The spatial boundaries option determines how room boundaries that are required for various energy 

calculations and quantity and material statements are exported. These boundaries are classified in 

levels, according to their purpose and the information that they contain: 

None does not export boundary surface information. Only the reference scope and reference to 

adjoining rooms and components are stored. 

Level 1 exports boundary surfaces for quantity and mass evaluation, taking room bounding elements 

into account. Openings created with the “Edit Profile” tool and surfaces edited with the “Split Faces” 

tool are not considered. 

Space boundaries: None Space boundaries: Level 1 



Level 2 exports boundary surfaces together 

with all data required for energy or thermal 

calculations. In this case, the boundary surfaces 

are influenced by the adjacent surfaces and 

their attributes, such as materiality. For energy 

calculations, boundary surfaces are associated 

with the building’s geometry. If the project is 

set up with phases, the desired phase for the 

export must be selected in the energy settings 

for the project: 

Project Origin 

Chose the origin of the exported file. There are 

4 options: 

- Current shared coordinates origin 

- Internal Revit coordinates 

- Project Base Point 

- Site Surve Point 

Split walls, supports, and air ducts by level 

divides these elements if they have been 

modeled over several floors. They are divided 

according to the floors of the building. This 

setting can be determined for each floor in the 

Revit properties. 



This view shows how important it is to define the right levels as floors, as otherwise the IFC structure 

becomes too confusing and the elements are not separated in an optimal way. Ideally, a project will 

have one level for each floor. There are certain cases when the next level is not the desired building 

story, like in split level houses. For such cases the level parameter “Story above” can be used to 

explicitly specify the next story. 

File Header information/project address allows general project information delivered with the IFC 

file to be customized. 

File information can be viewed with a text editor and, in addition to the optional information, 

automatically provides information about the original software, the IFC exporter, and the IFC 

schema. 

This information is mainly relevant to IFC exports for a CAFM platform in COBie format. We 

recommend using the COBie extension for Revit for this purpose. It is available at 

http://www.biminteroperabilitytools.com/. 



The project information is partly based on the location of the building (via address 

details). 

The information in the IFC export dialog can be used to supplement or overwrite 

these data. 



5.2.2 Additional content 

The following additional settings can be found in the tab for Advanced IFC export settings: 

Export plan view elements enables the export of some 2D elements such as grids, text, and lines. 

It is vital to ensure that the correct classes are used, such as IfcAnnotation or IfcGrid for grids. 

However, not all IFC viewers support the display of these classes. 2D support is restricted because 

the IFC format was designed to export BIM data, i.e. the 3D geometry, including the associated 

information. As such, it is not possible to export plan views. 

Export linked files as separate IFCs exports the Revit files that are currently linked within the 

project as separate IFC files. If this function remains deactivated, the Revit links are not exported. 

Export only elements visible in view includes only elements that are visible in the current view due 

to visibility settings, filters, and phases. 

Export spaces in 3D views generates IFC spaces and 3D volumes that can then be selected in an IFC 

viewer. 



5.2.3 Property sets 

The property sets tab in the advanced IFC export settings can be used to access various other key 

settings: 

Export Revit property sets allows you to export 

all the properties of a component. Although 

it might seem desirable at first glance, this 

function is not recommended for exchanging 

specialist IFC models. It augments the data 

model with lots of unnecessary information and 

thus has a negative impact on the file size. A 

data model exported via this option can be up 

to 70% bigger than one exported via another 

method. 

Export base quantities provides base quantities 

as a basis for determining quantities and creating 

simulations. During export, all elements are 

assigned as “base quantities” (fixed property 

sets defined by buildingSMART). For instance, a 

wall might look like this: 

Export IFC common property sets includes the 

default properties defined in the IFC schema. 

This option should always be activated. 



Export schedules as property sets enables the targeted export of properties that are defined in the 

schedules. As a Revit project usually contains lots of schedules, this option may be restricted to 

certain component lists by using only schedules with “IFC”, “Pset” or “default”’ in their name: 

Revit schedule and the resulting properties in the IFC file 

Export user defined property sets is another way of exporting specific selected properties. The 

parameters to be exported can also be specified in a text file. When Revit is installed, the default 

file is stored at this location: 

C:\ProgramData\Autodesk\ApplicationPlugins\IFC2018.bundle\Contents\2018\ 

DefaultUserDefinedParameterSets.txt 

It serves as the basis for the individual data sheet and is structured as follows: 

As a comparison, a completely configured data sheet might look like this: 



Please note: 

• A data sheet begins with a hash key. This allows several data sheets to be specified in a text file. 

• Parameters are separated using the tab key. 

• The name of the required data sheet follows a tab after the name PropertySet:; in the example 

above, this is specified as the “Autodesk parameter”. 

• Specifying “I” for instance or “T” for type determines whether this is a type or instance parameter. 

• The IFC classes of the elements to which these properties are assigned are then specified. This 

example applies only to walls, so “IfcWall” is used. 

• In the list that follows, the Revit parameters are shown on the left, followed by the IFC data type 

and the desired name of the IFC attribute, each separated with a tab. Note that calculated values 

such as the unlinked height of a wall cannot be transferred to the data sheet. 

In this example, the following instance 

properties of a wall are transferred: the phase, 

the space boundaries, and the supporting 

structure. It is important to specify the correct 

data type—normally “text,” “Boolean” for yes/ 

no parameters, “area” or “length.” If the IFC 

parameter does not have the same name as the 

Revit parameter, the latter can be specified at 

the end of the line. 

Export parameter mapping table allows the 

overwriting or extended assignment of certain 

parameters that are already defined in the IFC 

scheme, which are set out in the chapter on 

default attributes. 

The following example shows how custom 

properties can be mapped to standard parameters 

“Compartmentation” or “Combustible”. 

These can be defined in the mapping file as follows: 

Pset_WallCommon Compartmentation CustomParameter1 

Pset_WallCommon Combustible CustomParameter2 



The definition follows this principle: 

IFC_Common_PropertySet_NameIFC_Property_NameRevit_Property_Name 

is delivered with Revit. In this case, the building 

information modeling comes with unique key 

numbers for component properties, allowing 

machine processability and data linking. 

The supported property sets are defined in 

detail in the buildingSMART documentation 

online. A current list can be found at 


Revit affords the opportunity to use the 

standardized uniformity classification of 

components or a custom classification file. This 

is usually done by assigning the type property 

“assembly identifier”. This field allows you to 

select a pre-defined value from the classification 

file, which can be found in text format here: 

C:\ProgramData\Autodesk\Libraries\\UniformatClassifications.txt 

Classification settings allow you to specify the 

uniformity classification used in the project 

according to a country-specific system. In 

the UK, for instance, the Uniclass system is 

established as the means of classification, and 



This file can be adapted in line with the aforementioned local 

classification system. Information about Autodesk’s current 

modifications to these files can be found on the BIM blog: 


The specification in the IFC export dialog is merely information 

about which classification system is being used, and does not 

affect the actual content of the model: 



5.2.4 Level of detail 

The Level of detail tab in the IFC export settings can be used to select the following options: 

Level of detail for certain geometric elements enables you to set the level of detail. This has a 

significant impact on the file size and correct interpretation. 

Components should be exported with a high level of geometric detail only if needed, as it can cause 

data bloat. The Detail level “low” is usually sufficient. 



5.2.5 Advanced settings 

The last tab, Advanced, allows you to select the following additional options: 

Export parts as building elements is relevant 

to IFC data exchange when working with 

partial elements in the construction of walls 

or floor slabs. Partial elements are exported as 

“IfcBuildingElementPart” by default. This allows 

individual parts to be assigned to a higher-level 

element within the IFC data model: 

Example of a three-layered wall, exported as partial 

elements in the FZK viewer 

However, some BIM applications cannot 

interpret these special elements correctly, 

so that these are displayed in the IFC data 

model as separate wall elements without being 

assigned to a higher level. 

Allow use of mixed solid model representation 

enables the export of combined swept solid 

and B-rep models. A geometric object in an IFC 

data model is normally generated from either 

one or several swept solid objects, or from 

B-rep objects alone. The combination of these 

two types of representation is not enabled by 

default in the IFC schema. For more complex 

components, in particular, this leads either to 

a larger file size or incorrect presentation, as 

elements are wholly represented B-rep objects. 

Solid model representation combines the two 

types of representation within a single class, 



which can mean better geometric results at a 

smaller file size for complex models. It should be 

noted, however, that the IFC file exported using 

this setting no longer complies with the default 

IFC schema and must therefore be accepted as 

such by all those involved in the project. For 

certain areas of use, it may be necessary to have 

an unaltered default schema for export. 

Use active view when creating geometry 

incorporates the display settings for the current 

view into the IFC export and was specially 

developed for building equipment elements 

such as cable routes and built-in parts whose 

model geometry differs from the represented 

geometry: 

Fine representation vs. intermediate representation 

Use family and type names for reference enables referencing based on Revit family and type. The 

default setting is for referencing of a component based on the types used. 

Use 2D room boundaries for room volume simplifies the calculation of the room volume based on 

two-dimensional spatial boundaries. The space geometry from Revit is used to determine the volume 

in the IFC scheme by default. 



Include IFCSITE elevation in the site local 

placement origin: when exporting information 

about the site, the area (Ifc site) has a height 

value for the project. In IFC2x3 CV2.0, this 

value is set to “0” by default, which may not be 

interpreted correctly by older applications. The 

corresponding value is also provided with the 

help of this export setting. 

Store the IFC-GUID in an element parameter 

after export stores the generated IFC-GUIDs 

in the “IfcGUID” parameter after they have 

been successfully exported. This simplifies 

subsequent specialist model coordination, as 

the components are clearly identifiable. 

Export bounding box. Every geometrical element 

can also be represented in a simplified manner 

using a bounding box. If an object cannot be 

exported due to its complex geometry or needs 

to be simplified to better determine clearances, 

the bounding box can serve as an alternative to 

the representation itself or allow the object to 

be represented altogether. 

5.3 Other settings 

The class assignments made in the IFC export settings are formulated as defaults and form the 

basis for IFC export, with one IFC class assigned to each Revit category. 

In some cases, however, a finer division may be necessary, so that components are assigned to 

different IFC classes within a Revit category, often using the “Generic model” category. 

By using export parameters, these components can be assigned to specific IFC classes and types 

regardless of the default settings in the mapping table. 



IFC export parameters 

The following export parameters may be created: 

- IfcExportAs 

- IfcExportType 

- IfcName 

- IfcDescription 

- IfcObjectType 

- IfcLongName 

It is best to set up these parameters as 

“shared parameters” for project and family 

files. Autodesk provides a central IFC shared 

parameters text file, which can be downloaded 

here: https://autode.sk/IFClinks. 

According to the hierarchy, export parameters are above the default settings of the mapping table 

in the IFC export settings and thus overwrite the default settings. 

The parameter names are defined in the IFC format and are only taken into account if the spelling 

is correct. IFC export parameters should be assigned when they are integrated into the group “IFC 

parameters.” 



The parameters can be created as type or instance 

parameters as required, depending on the office 

standard. In general, it is recommended that 

you use type parameters, as these data rarely 

vary between individual instances of the same 

type. 

The “IfcExportAs” parameter overwrites the 

default IFC class of a Revit component for the 

IFC export, e.g. IfcSlab for slabs. The parameter 

value “DontExport,” on the other hand, prevents 

the creation of a component type when exporting 

the data model. 

The “IfcExportType” parameter overwrites the 

default type for the IFC export. This parameter 

is not used often because the type can also be 

defined using the IfcExportAs parameter, where 

the type is separated after the class with a colon, 

e.g.. “IfcSlab.ROOF” for a slab of the roof type. 

In certain cases it can be useful to override 

certain information during the export, such 

as IfcName, IfcDescription, IfcObjectType, 

IfcLongName. While these are the preferred 

names for the overrides, Revit currently also 

supports NameOverride, DescriptionOverride, 

ObjectTypeOverride, LongNameOverride. In 

terms of its actual function these parameters 

should not be considered as export parameters, 

but they have the ability to overwrite the default 

values such as type and generate the associated 

property data sheets. 

Behavior of system families 

System families such as walls, ceilings, floor slabs, stairs, and ramps can only be assigned to other 

classes to a limited extent in Autodesk Revit. The basic rule for system families is that, based on 

their type of application and geometrical representation in Revit, objects can only be assigned to a 

certain group of classes. 



Behavior of project families 

A family created within the project can be assigned to any class officially supported by Autodesk 

using the IfcExportAs parameter. 

Behavior of loadable families 

Essentially, loadable families behave like project families and can be assigned to any supported 

class. It is also possible to assign nested families to different classes and types of IFC export. 

It is important to ensure that the “shared” option is activated in the properties of the individual 

families. 

Voids are also automatically assigned to the OpeningElement class. 

When creating a project family as a void, this is also automatically assigned to the corresponding 

OpeningElement class. 



6 USECASES 

6.1 Floor slab construction 

Floor slabs are often modeled using two separate elements: the supporting floor slab is modeled 

before the floor structure is added as a multi-layer floor for each room: 

For IFC export, all floor slabs are assigned to the IfcSlab class. This may prove a hindrance to 

further planning or assignment in AVA or calculation software. Instead, it makes sense to export 

the floor not as IfcSlab, but as IfcCovering, which also assigns it the appropriate attributes, such as 

combustibility or surface finish. 

As such, for both floor constructions, the IfcExportAs parameter is specified as “IfcCovering. 

FLOORING,” which assigns the elements to the IfcCovering class and the FLOORING type on export: 



This assignment gives the floor construction 

the right class/type and the properties defined 

in the Pset_CoveringCommon, which facilitates 

further evaluations: 

6.2 Cut openings 

The use of placeholders has largely been 

established in the planning and coordination of 

cut openings in the BIM process, as “provision 

for void” objects. These can be exchanged 

between specialist models, including all the 

necessary information and dimensions, and can 

also be used for approval processes and the 

eventual creation of the aperture itself. 

Optionally, the family may also include another 

solid form extrusion, which is controlled 

using a visibility parameter and has the same 

dimensions as the void. With the help of this 

second solid, a specialist model may be created 

separate from the overall model as an IFC 

file, specifically for the purposes of aperture 

planning. 

These may be based either on aperture elements 

from the Revit library or a simple family with a 

void. 

Using a component filter and a coordinated 3D 

export view allows you to visualize and export 

the provision for void solid as a specialist 

model. 



Overall model view 

with planned aperture 

3D view with view filter and superimposed 

aperture solids 

In addition, 2D breakthrough symbols for sectional and plan views can also be added to this family. 

For IFC export, the aperture family is given the following data: 

Revit component IfcExportAs IfcObjectTypeOverride 

Void IfcBuildingElementProxy PROVISIONFORVOID 

By assigning the type, the aperture is provided with all the necessary information: 



6.3 Assigning assemblies 

Assemblies are important for the higher-level grouping of components and are often used for truss 

fields, beam grids and reinforcement cages. Unlike the grouped elements in Revit, the assemblies 

are also transferred during IFC export and can have higher-level properties. 

The reinforced bars and brackets of a floor slab are assigned to an assembly in this example: 

The IFC parameters are overwritten in the process: 

Revit component IfcExportAs IfcObjectTypeOverride 

Reinforcement IfcElementAssembly REINFORCEMENT_UNIT 

In the IFC data model, assigning this class and applying the instance parameter “IfcObjectTypeOverride’” 

defines the predefined type as “REINFORCEMENT_UNIT” and aggregates the higher-level assembly 

as “IfcElementAssembly.” 

The individual assembly elements can still be selected separately. This assignment provides a better 

structure within the IFC model for the evaluation and classification of components. 



6.4 Assigning default attributes 

BuildingSMART provides appropriate information about default attributes as part of its online 

documentation. Under the term “Pset_CoveringCommon,” for instance, you can find all the default 

attributes of the entity class “IfcCovering.” 

For a list of the property data sheets for architectural components of the IFC4 schema with 

multilingual explanations, see 

http://www.buildingsmart-tech.org/ifc/IFC2x4/rc3/html/schema/ifcsharedbldgelements/pset/ 

The attributes made available are determined by the choice of class or type. 

As an example, “Pset_CoveringCommon” has been specified here, so that all elements of the 

IfcCovering class are automatically assigned: 

IFC-Attribute 

Revit parameter 

Reference 

Status 

AcousticRating 

FireRating 

Combustible 

SurfaceSpreadOfFlame 

ThermalTransmittance 

IsExternal 

LoadBearing 

Compartmentation 

FlammabilityRating 

FragilityRating 

Finish 

Component type 

Construction phase for the element 

Sound insulation class 

Fire-resistance class 

Combustible material 

Fire behavior 

U-value 

Exterior component 

Load-bearing component 

Fire compartment-defining component 

Flammability rating 

Fragility class 

Surface finish 

When exporting, please note that only Revit parameters that exist in the project and show the 

correct unit and a valid value are included. “Empty” parameters are not exported. 



Creating selected attributes in Revit projects 

Due to the amount of data, it does not make sense to provide all the available attributes in a single 

template. Adding the necessary attributes as required is more practical. 

Autodesk provides its own IFC shared parameters file, which already contains all the available 

parameters. For the link to this file, see 


The correct units for the parameters are predefined in this file. The parameters can be defined either 

as type or as instance parameters. Ultimately, this depends on the specific company standard and 

way of working. 

As a result, the newly created attributes are assigned to the corresponding “Pset” during export. The 

following comparison shows the basic contents and the contents after the corresponding attributes 

have been assigned: 

Basic contents Pset_CoveringCommon 

Contents after assignment Pset_CoveringCommon 



6.5 Structuring the IFC data model 

When exchanging models, not all the information 

generating in the course of the planning process 

is relevant. Often, many reference levels are 

used, for instance, that are ultimately irrelevant 

to the model transfer. As such, only certain 

levels tend to be identified and exported as 

story levels. 

The export of story levels is influenced by the 

corresponding “Story level” parameter in the 

Revit properties for a level. All components on 

other levels are assigned to the nearest story 

level. Ideally, only one defined story level 

should exist for each story of the building. 

In the next example, the shared parameter 

“IfcName” is used to rename the levels when 

they are exported. This also overwrites the 

predefined name for most of the other Revit 

elements. 

The “IfcName” parameter is created as a text 

parameter and can be assigned to the desired 

Revit categories as a project parameter 

(instance or type parameter). The parameter 

“Ifc-Description” can also be created in the 

same way. This attribute can be used to append 

additional information to an element. 

Such customization results in the renaming and 

additional description of the corresponding 

level: 



Default name after IFC export 

Level name with additional notes 

If required, the building floor can be assigned other attributes in a similar way to other components. 

The basis for the assignment of default attributes is the 

“Pset_BuildingStoreyCommon.” 

6.6 Usage groups in the IFC data model 

Usage groups can also be stored within the 

IFC data model. Based on an export schema 

generated in Autodesk Revit, these groupings 

can be passed on to those involved in the project 

for further use. 

The export of usage groups and zones is based 

on the parameter “ZoneName.” This is assigned 

as a shared parameter (type: text) of the Revit 

category “Rooms.” Only one instance parameter 

can be used for this category. 

Using this parameter, you can then generate a 

color scheme for rooms/zones and create the 

necessary categories: 

Schema definition using the 

parameter “ZoneName” 

In a floor plan, the corresponding categories of 

the color scheme can now be assigned to the 

generated rooms: 

Schema assignment for the room 

properties in Autodesk Revit 



During the subsequent IFC export, the respective 

rooms are assigned to the corresponding usage 

groups. 

It is also possible to assign several usage 

groups to a room. To do so, it is necessary to 

create additional “ZoneName” parameters and 

to number these in ascending order (“ZoneName 

2, ZoneName 3...”). 

Stored usage groups in the IFC model 

6. SUMMARY 

Building Information Modeling (BIM) provides everyone involved in a building design and 

construction project with new opportunities to make well-informed project decisions, communicate 

better, optimize workflows, and improve documentation. The data exchange functions provided by 

openBIM and IFC allow all of those participating in a project to work together, even if they use 

different software products. 

More information about BIM, openBIM, and IFC is available via these links: 

https://www.autodesk.com/solutions/bim 

https://www.autodesk.com/solutions/bim/hub/bim-interoperability 

http://buildingsmart.org/ 



Autodesk, Inc. 

111 McInnis Parkway 

San Rafael, CA 94903 

https://www.autodesk.com/solutions/bim/ 

hub/bim-interoperability 

Note: Autodesk ® Revit ® provides certified IFC export and import according to the building-SMART 

IFC 2x3 Coordination View data exchange standard. 

This includes certifications for architectural, structural, and MEP data in line with the buildingSMART 

IFC 2x3 Coordination View 2.0 data exchange standard of March 2013 and April 2013. Revit received 

Grade 1 IFC 2x3 Coordination View Certification in June 2006 and full Grade 2 certification for 

Coordination View in May 2007. 

Apart from these certifications, buildingSMART has not hitherto issued any other certificates for 

architectural design software. 

Autodesk, the Autodesk logo, AutoCAD, BIM 360, DWF, DXF, Glue, Navisworks, and Revit are 

registered trademarks or trademarks of Autodesk Inc. and/or its subsidiaries or affiliates in the 

USA and/or other countries. All other trademarks, product names, and other characteristics are the 

property of their respective owners. Autodesk reserves the right to change its products, services, 

specifications, and prices at any time without prior notice, and is not liable for any typographical or 

graphical errors in this document. 

©2018 Autodesk Inc. All rights reserved.

REVIT IFC MANUAL

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